At about 1 p.m., a fire and series of explosions occurred at a chemical distribution facility. The initial fire started in the packaging area while a 300-gallon portable steel tank, known as a tote, was being filled with ethyl acetate, a flammable solvent.

An operator placed the fill nozzle in the fill opening on top of the tote and suspended a steel weight on the nozzle to keep it in place (otherwise, pressure from the liquid flowing through the nozzle can cause it to dislodge during filling). After opening the valve to begin the filling process, the operator walked across the room to do other work. As the tote was filling, he heard a “popping” sound and turned to see the tote engulfed in flames and the fill nozzle laying on the floor discharging ethyl acetate. Before evacuating, employees tried unsuccessfully to extinguish the fire with a handheld fire extinguisher. The fire spread rapidly to the wood-framed warehouse (with no specific fire protection), igniting a large volume of flammable and combustible liquids.

One employee received minor injuries and one firefighter was treated for a heat-related illness. A large plume of smoke and rocketing barrels and debris triggered an evacuation of the businesses surrounding the facility. The main warehouse structure was destroyed and the business was significantly interrupted.

The Chemical Safety Board (CSB) investigated the accident and concluded that static electricity likely accumulated on the steel parts of the fill nozzle and hose assembly (and the steel weight) because they were not bonded and grounded, and sparked to the stainless steel tote body, igniting the vapor that accumulated around the fill opening during filling.

The tote was sitting on a grounded weigh scale while being filled, and according to witnesses, the operator attached a grounding clamp to the tote before he started filling it. However, the metal components of the nozzle, the synthetic rubber fill hose, and the pump were not bonded to the tote.

The nozzle was made of nonconductive plastic, but it housed a stainless steel ball valve and was fitted with a steel quick-connect fitting. The steel weight (suspended from the ball valve handle with a length of steel wire) was intended to prevent the nozzle from being ejected from the tote during filling. All these conductive objects were isolated from ground and were susceptible to static accumulation and discharge. The manufacturer’s technical documentation for the nozzle and hose revealed that they were not intended for flammable service.